1. Field of the Invention
The invention relates to an extruder that converts preferably granular plastic material into the melted state and which includes at least one cylinder in which an extruder screw rotates, which is connected with a drive unit to at least one motor so that the drive unit provides the torque for the rotary motion of the extruder screw, the motor being allocated one or more rotors. The invention also relates to a process for operating such an extruder.
2. Description of the Related Art
Plastic film extruders of the above-described type are used usually to convert plastic raw material into a melted state, which is suitable for further processing. These extruders are used predominantly in extrusion lines, as also presented in the DE 199 31 147.
The extruder screws are driven with drive units, which are connected either rigidly to the extruder screws via drive unit mechanisms, or impart with the extruder screws the necessary torque via a chain or belt connection.
The drives used in both cases are expensive and have a large space requirement.
Therefore, the object of the present invention is to propose a device and a process that render these drives superfluous.